RESUMO
Improper discharge of cassava mill effluent (CME) has attracted much attention in major cassava-producing areas due to cyanide contamination. This study conducted a target survey on inhabitants and processors of the Akrofrom-Techiman cassava processing area in Ghana that aimed to assess their knowledge and perception of cyanide contamination from the CME discharge. The study further examined the effect of CME on the soil and groundwater at the processing area using physicochemical and bacteriological characterizations. Results revealed that inhabitants and processors exhibited high illiteracy on the impact of CME on cyanide contamination in the processing area. The study also indicated a wide characteristics of the soil at the processing site: pH (4.89-8.77), electrical conductivity (EC) (1063.00-1939.00 µS/cm), total dissolved solids (TDS) (523.90-963.50 mg/L), soil moisture (11.90-31.70%), free cyanide (0.02-0.33 mg/kg), and total cyanide (0.40-2.70 mg/kg). Results also showed that the physicochemical values of the CME were all above the Ghana Environmental Protection Agency (EPA) permissible limits and were unsafe for discharging into the environment. The range of physicochemical and bacteriological parameters of the two boreholes revealed the following: pH (7.85-8.74), TDS (165.77-192.37 mg/L), EC (320.87-396.20 µS/cm), free cyanide (0.13-0.16 mg/L), total cyanide (1.29-2.15 mg/L), and bacteriological parameter (220-622 cfu/mL). The two hand-dug wells also recorded pH (8.54-9.56), TDS (140.77-156.10 mg/L), EC (288.53-340.67), biological oxygen demand (BOD) (21.51-1.61 mg/L), chemical oxygen demand (COD) (13.5-16.5 mg/L), free cyanide (0.10-0.11 mg/L), bacteriological parameter (241-302 cfu/mL), and total cyanide (0.79-0.86 mg/L). The study concluded that the discharge of CME at the processing site contributes significantly to cyanide contamination of the soil and groundwater at the processing area.